Since dye-sensitized solar cell elements as photoelectric conversion elements can obtain high photoelectric conversion efficiency with a low cost, the dye-sensitized solar cell elements have drawn much attention, and thus, various developments of the dye-sensitized solar cell elements have been made.
The dye-sensitized solar cell element includes at least one dye-sensitized solar cell, and the dye-sensitized solar cell typically includes a working electrode and a counter electrode. The working electrode includes a transparent substrate, a conductive substrate having a transparent conductive film formed thereon, and an oxide semiconductor layer provided on the conductive substrate.
With respect to such a dye-sensitized solar cell element, improvement of the photoelectric conversion characteristics is further required. For this reason, various studies have been made, for example, while paying attention to the working electrode of the dye-sensitized solar cell.
For example, Patent Document 1 discloses a photoelectrode including a conductive substrate and a semiconductor layer to which a photosensitizing dye is adsorbed, where the semiconductor layer includes a proximal layer provided on the conductive substrate and a distal layer provided to cover at least a part of a surface of a side opposite to the conductive substrate and a side surface among surfaces of the proximal layer.